43 research outputs found
A TGA-based Method for Safety Critical Plan Execution
Safety critical planning and execution is a crucial issue in autonomous systems. This paper proposes a methodology for controller synthesis suitable for timeline-based planning and demonstrates its effectiveness in a space domain where robustness of execution is a crucial property. The proposed approach uses Timed Game Automata (TGA) for formal modeling and the UPPAAL-TIGA model checker for controllers synthesis. An experimental evaluation is performed using a real-world control system
polymer nanostructuring by two photon absorption
Two-photon polymerization (2PP) is an innovative technology that in recent years showed a tremendous potential for three-dimensional structuring of photopolymers at the submicron scale. It is based on the nonlinear absorption of ultrashort laser pulses in transparent photosensitive materials. 2PP has been so far exploited in various fields, including photonics, microfluidics, regenerative medicine and MEMS prototyping. The versatility of this technology relies also on the photomaterials; indeed, polymers are easy to process, low cost and they allow the tailoring of their chemical and mechanical properties. 2PP nanotechnology is here exploited to produce micro and nanostructures that can be easily customized both in the geometry and in polymer functionalization. In particular, atomic force microscopy tips are fabricated on top of commercial cantilevers to demonstrate the technology feasibility and customizability. Moreover nanoporous membranes that can be fabricated by 2PP as a single custom product or as a mould for mass production through replica moulding are realized to evaluate the scalability of the fabrication process
Recurrent malignant schwannoma of the parapharyngeal space in neurofibromatosis type 1.
Malignant schwannoma is an aggressive tumor that carries a poor prognosis despite wide excision, chemotherapy, and radiotherapy. Malignant schwannoma of the parapharyngeal space is an uncommon find..
Fabrication of Biocompatible Monolithic Microchannels with High Pressure-Resistance Using Direct Polymerization of PEG-modified PMMA
Withstanding high pressures in polymeric microchannels is an important requirement for many biological applications. Here, a simple direct polymerization through a polyester photomask is applied to obtain monolithic polyethylene glycol (PEG)-modified poly(methyl methacrylate) (PMMA) (PEGMA) microchannels, showing the ability to withstand pressure up to 12 MPa in burst pressure tests. The ability of withstanding high pressures is observed to increase with increasing ratio between the thickness of the cover polymer layer forming the microchannel lid and the width of the microchannel. A simplified finite element modeling model of the burst pressure test is set up to interpret the experimental findings. The outcomes of the modeling activity, along with direct scanning electron microscopy observation of the fracture surfaces, confirm the effectiveness of the polymerization method for the production of monolithic PEGMA microchannels. (C) 2014 Wiley Periodicals, Inc
Parapharyngeal high-grade malignant schwannoma with extension to infratemporal and pterygopalatine fossa
[No abstract available