Diaspora, return and migrant architectures

Nearly all discourses on migration (to my knowledge) emphasise that the migrant is not so much a traveller, but a figure oriented towards settlement and a particular destination. Discourses on migration have attended more to the process and site of ‘arrival’, and few studies have focused on the process and site of ‘departure’. However, central to the thesis of this paper would be the testimony of two migrant houses – one in the city of  immigration (Melbourne, Australia), and the other in the village of emigration (Zavoj in Macedonia). The focus will be on the Zavoj house as a significant house, a house that points to a thesis about how architecture makes explicit other processes of migration, namely that of ‘return’. Here there are several intertwined communities and nations, and also different notions of community and nation. It has been noted that ‘diaspora’ is constituted through longer distances, severe separation, and a taboo on return. And yet implicit in many more ‘autobiographical’ accounts is that one only leaves with a promise to return. The conflict and question of ‘return’ is at the centre of the migrant’s imaginary. A study of the two houses of migration implicates a set of networks, forces, relations, circumscribing a much larger global geopolitical and cultural field that questions our understandings of diaspora, the currency of transnationalism, the binary structure of dwelling/travelling, and the fabric and fabrication of community. But the study goes inwards and underneath as well through the figure of the migrant, the figure through which the two migrant houses are deeply associated. The paper will explore the subjective nature of the thesis, the idea of a ‘migrant house’ as an imaginary architecture, a psychic geography, an imaginary community and sense of nationhood.

Application of radial return mapping algorithm for finite strain elastoplasticity in a hybrid finite element and particle-in-cell model

The radial return mapping algorithm within the computational context of a hybrid Finite Element and Particle-In-Cell (FE/PIC) method is constructed to allow a fluid flow FE/PIC code to be applied solid mechanic problems with large displacements and large deformations. The FE/PIC method retains the robustness of an Eulerian mesh and enables tracking of material deformation by a set of Lagrangian particles or material points. In the FE/PIC approach the particle velocities are interpolated from nodal velocities and then the particle position is updated using a suitable integration scheme, such as the 4th order Runge-Kutta scheme[1]. The strain increments are obtained from gradients of the nodal velocities at the material point positions, which are then used to evaluate the stress increment and update history variables. To obtain the stress increment from the strain increment, the nonlinear constitutive equations are solved in an incremental iterative integration scheme based on a radial return mapping algorithm[2]. A plane stress extension of a rectangular shape J2 elastoplastic material with isotropic, kinematic and combined hardening is performed as an example and for validation of the enhanced FE/PIC method. It is shown that the method is suitable for analysis of problems in crystal plasticity and metal forming. The method is specifically suitable for simulation of neighbouring microstructural phases with different constitutive equations in a multiscale material modelling framework.

Inverse opal nanoassemblies : novel architectures for gas sensors the SnO2:Zn case

A novel technique is here presented, based on inverse opal metal oxide structures for the production of high quality macro and meso-porous structures for gas sensing. Taking advantage of a sol-gel templated approach. different mixed semiconducting oxides with high surface area, commonly used in chemical sensing application, were synthesized. In this work we report the
comparison between SnO₂ and SnO₂:Zn. As witnessed by Scanning and Transmission Electron Microscopy (SEM and TEM) analyses and by Powder x-ray Diffraction (PX RD), highly ordered meso-porous structures were formed with oxide crystalline size never exceeding 20 nm . The filled templates. in form of thick films, were bound to allumina substrate with Pt interdigitated contacts
and Pt heater, through in situ calcination, in order to perform standard electrical characterization. Pollutant gases like CO and NO₂ and methanol. as interfering gas, were used for the targeted electrical gas tests. All samples showed low detection limits towards both reducing and oxidizing species in low temperature measurements. Moreover, the addition of high molar percentages of Zn( II) affected the beha viour of electrical response improv ing the se lecti vity of the proposed system.

The adoption of web services based architectures in Australian organisations : an exploratory study

This exploratory research study contributes to answering two related research questions. First it identifies the key influences that seem to be driving and constraining the adoption of Service Oriented Architecture (SOA) and XML/Web Services and secondly it adduces some evidence to confirm that these influences significantly differ from those found by IS researchers in the adoption of other innovations in organisations. The key drivers were found to include improved agility, reuse and [open standards enabled] interoperability. None of these map easily to factors identified in previous Diffusion of Innovations (DOI) related IS research. In spite of standards being originally seen as strengths, it was found that the lack of IT industry agreement on the next generation of Web Services standards is now emerging as a perceived constraint. Variants of the ‘network effect’ such as partner push and client drag were also found to be influential.

Interobserver reliability of radial head fracture classification : two-dimensional compared with three-dimensional CT

Background: The Broberg and Morrey modification of the Mason classification of radial head fractures has substantial interobserver variation. This study used a large web-based collaborative of experienced orthopaedic surgeons to test the hypothesis that three-dimensional reconstructions of computed tomography (CT) scans improve the interobserver reliability of the classification of radial head fractures according to the Broberg and Morrey modification of the Mason classification.

Methods: Eighty-five orthopaedic surgeons evaluated twelve radial head fractures. They were randomly assigned to review either radiographs and two-dimensional CT scans or radiographs and three-dimensional CT images to determine the fracture classification, fracture characteristics, and treatment recommendations. The kappa multirater measure (κ) was calculated to estimate agreement between observers.

Results: Three-dimensional CT had moderate agreement and two-dimensional CT had fair agreement among observers for the Broberg and Morrey modification of the Mason classification, a difference that was significant. Observers assessed seven fracture characteristics, including fracture line, comminution, articular surface involvement, articular step or gap of ≥2 mm, central impaction, recognition of more than three fracture fragments, and fracture fragments too small to repair. There was a significant difference in kappa values between three-dimensional CT and two-dimensional CT for fracture fragments too small to repair, recognition of three fracture fragments, and central impaction. The difference between the other four fracture characteristics was not significant. Among treatment recommendations, there was fair agreement for both three-dimensional CT and two-dimensional CT.

Conclusions: Although three-dimensional CT led to some small but significant decreases in interobserver variation, there is still considerable disagreement regarding classification and characterization of radial head fractures. Three-dimensional CT may be insufficient to optimize interobserver agreement.

Incorporation of fused tetrathiafulvalenes (TTFs) into polythiophene architectures : varying the electroactive dominance of the TTF species in hybrid systems

A novel polythienylenevinylene (PTV) and two new polythiophenes (PTs), featuring fused tetrathiafulvalene (TTF) units, have been prepared and characterized by ultraviolet−visible (UV−vis) and electron paramagnetic resonance (EPR) spectroelectrochemistry. All polymers undergo two sequential, reversible oxidation processes in solution. Structures in which the TTF species is directly linked to the polymer backbone (2 and 4) display redox behavior which is dictated by the fulvalene system. Once the TTF is spatially removed from the polymer chain by a nonconjugated link (polymer 3), the electroactivity of both TTF and polythiophene moieties can be detected. Computational studies confirm the delocalization of charge over both electroactive centers (TTF and PT) and the existence of a triplet dication intermediate. PTV 4 has a low band gap (1.44 eV), is soluble in common organic solvents, and is stable under ambient conditions. Organic solar cells of polymer 4:[6,6]-phenyl-C₆₁ butyric acid methyl ester (PCBM) have been fabricated. Under illumination, a photovoltaic effect is observed with a power conversion efficiency of 0.13% under AM1.5 solar simulated light. The onset of photocurrent at 850 nm is consistent with the onset of the π−π absorption band of the polymer. Remarkably, UV−vis spectroelectrochemistry of polymer 4 reveals that the conjugated polymer chain remains unchanged during the oxidation of the polymer.

AlN nanostructures : tunable architectures and optical properties

Novel AlN nanostructures with tunable building units of the architectures have been successfully synthesized without any catalyst or template; the subsequent photoluminescence (PL) indicates that the optical properties of the AlN nanostructures can be adjusted by tuning the architectures.