Higher Institute on Territorial Systems for Innovation
PORTO Publications Open Repository TOrinoNot a member yet
91193 research outputs found
Sort by
Viewpoints and visibility analysis: a case study on the UNESCO site of Langhe-Roero and Monferrato (Piemonte Region)
No full textThe present work is based on the coupling between the visibility analysis based on viewsheds/cumulative viewsheds (binary maps) and the study conducted at a regional level that identifies points that can be considered and that should be preserved. Visual landscape assessment methods can now exploit the resources that public administrations shares within the open data normative requirements. This implies a further valorisation of the investments done though the creation and update of geographical data. The scope of this work is not to obtain a static map, but to set out an interactive tool that, based on visibility analyses, can be used to measure the landscape sensitivity of sites. The area named "Vineyard Landscape of Piedmont: Langhe-Roero and Monferrato ", listed as the 50th Italian site in the World Heritage UNESCO list, was identified as a case study, since it is a cultural landscape of exceptional and universal value. The information provided by this application may be used into the regulatory framework for all the authorization process of new developments in preserved areas. The objective is to provide technicians and local administrators tools based on objective data for the conservation, preservation and valorization of the landscape on one side, and for the development of economic activities that can promote a sustainable development of such peculiar locations
A new approach for the development of DLP-3D printable functional materials
No full textWithin the advances in computer and processing technologies, new manufacturing processes known under the name of Additive manufacturing (AM), have broken into public consciousness over the past last years. Additive Manufacturing Technologies (AMT), popularly known as 3D printing, have become appealing methods for the fabrications of solid forms with controlled geometry. AM is an umbrella term for a group of technologies that can produce highly complex three dimensional objects using data generated by Computer Aided Design (CAD) systems without tools or molds. 3D techniques work using the concept of layered manufacturing: objects are fabricated layer by layer and produced through the addition of materials. The additive approach of manufacturing provides a cost-effective and time-efficient way to produce low-volume, customized products with complicated geometries and advanced material properties and functionality. Currently there are over thirty different types of additive manufacturing technologies. Their operation can be based on different physical principles and requires the use of different materials, however all have as their common denominator, the distinction of building the object layer by layer. The type of 3D printer chosen for an application often depends on the materials to be used and on the resolution needed. 3D printing technologies can be classified under seven main groups based on their mechanism: materials extrusion based methods, powder bed fusion methods, directed energy deposition methods, binder and material jetting methods, sheet lamination methods and photopolymerization (light induced) methods. Among the various 3D printing approaches, in my PhD l focused on photopolymerization based 3D printing methods. The main 3D technologies of this groups are: stereolithography (SLA) and digital light processing (DLP). In these techniques, the chemical process underlying the construction of the layers, and the creation of 3D objects, is the photopolymerization. Recently, 3D printing has rapidly grown and has shown great potential in various application fields, spanning from bioengineering, to microfluidics and electronics. There is a growing interest for 3D printing focused to the production of functional structures. The possibility to obtain functional elements by means of a 3D printer, such as batteries, antennas, membranes, sensors etc. is one of the key points of the evolution of this technology. Such a breakthrough requires a simultaneous development in new printing technologies and new materials. A constant effort to enhance and to extend the functionality of printing to meet the specific requirements of various applications is needed. The materials used in printing must undergo several developments: resolutions must continue to improve, building time must continue shortening and, in particular, more types of materials must become available. Great strides have been made in all these areas in the past years but the innovation is still on going. A robust choice of materials and the ability to control and predict their performance are essential to achieve broader use of 3D printing. Engineered materials specifically studied for being 3D printable, exhibiting optimized properties and multifunctionality, will offer huge potential and opportunities in myriad applications, resulting in better functionality of the manufactured device (e.g, biocompatibility, electrical conductivity, optical response, chemical sensitivity, mechanical behavior...) coupled with improved printability. The main approaches in the evolution of 3D printable materials consist in working with multiple materials or nanocomposite to create new combinations that have unique properties expanding the range of 3D printable materials. The research conducted during my PhD is centered in this frame, focusing on the development of new polymer nanocomposites for 3D printing technologies based on photopolymerization, in particular for digital light processing (DLP). With such technique, it is possible to tailor the final properties of the printed object by simply changing the reactive light-sensitive liquid formulations: a large variety of systems can be conceived to produce functional structures. The addition of nanofillers to the formulations could help in reaching the desired functionalities but, at the same time, it could modify the printing process introducing new issues: increased viscosity, limited light penetration depth, nanoparticles dispersion and stability. For these reasons, the strategy developed during my PhD consisted in realizing multifunctional materials by simply operating on the chemistry of the systems without affecting the printability. Using a "bottom-up approach", liquid or soluble precursors of the desired nanoparticles can be added to the formulation in order to obtain the required functionality directly into the printed piece through a post processing step. Using this bottom-up approach two different works have been carried on. In the first work silica nanodomains were directly generated in a photocured 3D structured matrix dispersing metal alkoxide liquid precursors in the initial formulation and submitting the printed part to a sol-gel post-process in acidic vapors. The post sol-gel treatment in acidic vapors allowed the in-situ generation of the inorganic phase in a dedicated step. This method allows to build hybrid structures operating with a full liquid formulation without meet with the drawbacks of incorporating inorganic powders into 3D printable formulations. Following the same strategy, the second work deals with the incorporation of silver nitrate into a reactive mixture in order induce the in-situ generation of silver nanoparticles during a thermal or UV post processing of the printed object. The developed process allows a good distribution of the metal nanoparticles in the polymer matrix, producing very complex geometries with improved electrical properties. In the last chapter of the this thesis, Chapter 4, I summarize the activity conducted during my exchange period in the laboratory of Micro-Nano-Bio Systems Laboratory (MNBS Lab) of Prof. Jun Yang, University of Western Ontario Canada. During this period, I have familiarized with the use of 3D technologies for the fabrication of conductive hydrogels. Conductive polymer hydrogels are promising materials, especially in bio-medical and bio-electronics fields. They showed great potential in drug release, bioactive electrode, actuator and as scaffolds for tissue engineering. However, it is extremely challenging to build this hydrogel in complex 3D structures with conventional fabrication methods. The idea of the work was to couple 3D printing with interfacial polymerization in order to obtain electro-active hydrogels with complex and defined geometry. Polypyrrole/PEGDA conductive hydrogels were fabricated through a two-step procedure. First 3D printing technology was used to fabricate PEGDA microstructures, functioning as the supportive structure. Second, by means of interfacial polymerization (IP), pyrrole (PY) was polymerized at the interface, leading to the formation of polypyrrole (PPY) into the hydrogel matrix, thus synthesizing a conductive hydrogel. All the approaches presented in the thesis allowed to build nanocomposites structures operating with a full liquid formulation without meeting the drawbacks of incorporating inorganic fillers into 3D printable formulations. In all the works, the composites prepared present excellent printability and mechanical stability saving the high accuracy of the 3D process. These works open the possibility of developing functional objects with complex geometries through simple but very efficient processes
Interfacial effects in solid-liquid glyme electrolytes for improved performance of DSSCs
No full textThe electrolyte is one of the crucial components in dye sensitized solar cells (DSSCs), allowing for fast diffusion of charge carriers between the electrodes and directly affecting photocurrent density (JSC), photovoltage (VOC), and fill factor (FF). Quasi-solid state DSSC electrolytes typically ensure mechanical properties of a solid and diffusive property of a liquid, circumventing practical problems such as solvent volatility, leakage, photodegradation and corrosion of counter electrode. In this study, a polyethylene glycol dimethyl ether (PEGDME, Mw = 150 g mol-1) based I-/I3- electrolyte containing mesoporous SiO2 particles (MSU-H, 15 nm pores) is investigated in terms of ionic conduction and DSSC performance. Similarly as in "soggy sand" electrolytes, preferential adsorption of anions is observed by Zeta potential measurements and ionic conductivity of the liquid electrolyte can be enhanced. High values of photovoltaic parameters at 1 sun irradiation (JSC = 11.5 mA cm‒2, VOC = 0.69 V, FF = 0.47, 6.3% efficiency) at 3.8 vol % SiO2 suggests an improved regeneration kinetics of the dye molecules. Transient photocurrent experiments confirmed favorable mass transport. A remarkably high 14.3% efficiency was measured under 0.2 sun irradiation
Personal Cloud Storage Benchmarks and Comparison
No full textThe large amount of space offered by personal cloud storage services (e.g., Dropbox and OneDrive), together with the possibility of synchronizing devices seamlessly, keep attracting customers to the cloud. Despite the high public interest, little information about system design and actual implications on performance is available when selecting a cloud storage service. Systematic benchmarks to assist in comparing services and understanding the effects of design choices are still lacking. This paper proposes a methodology to understand and benchmark personal cloud storage services. Our methodology unveils their architecture and capabilities. Moreover, by means of repeatable and customizable tests, it allows the measurement of performance metrics under different workloads. The effectiveness of the methodology is shown in a case study in which 11 services are compared under the same conditions. Our case study reveals interesting differences in design choices. Their implications are assessed in a series of benchmarks. Results show no clear winner, with all services having potential for improving performance. In some scenarios, the synchronization of the same files can take 20 times longer. In other cases, we observe a wastage of twice as much network capacity, questioning the design of some services. Our methodology and results are thus useful both as benchmarks and as guidelines for system design
Train the trainers on learn geometry by doing
No full textIn this paper we describe how, starting from our experience of Geometry's teaching in two different academic contexts (mathematic and drawing), we identified together common didactics tools in order to educate the reading of the geometric shapes and their properties with particular attention to the architectural cases. To do this we use 3D models (for example origami models) and gaming activities, both with students and with trainers and our lessons are held not only in the classroom but in public places such squares or cultural sites. Today, we use our teaching idea to train the trainers to understand how to teach geometry in each kind of school level in a new way, using a tangible geometry
Optimized Deep Neural Networks for Real-Time Object Classification on Embedded GPUs
No full textConvolution is the most computationally intensive task of the Convolutional Neural Network (CNN). It requires a lot of memory storage and computational power. There are different approaches to compute the solution of convolution and reduce its computational complexity. In this paper, a matrix multiplication-based convolution (ConvMM) approach is fully parallelized using concurrent resources of GPU (Graphics Processing Unit) and optimized, considerably improving the performance of the image classifiers and making them applicable to real-time embedded applications. The flow of this CUDA (Compute Unified Device Architecture)-based scheme is optimized using unified memory and hardware-dependent acceleration of matrix multiplication. Proposed flow is evaluated on two different embedded platforms: first on an Nvidia Jetson TX1 embedded board and then on a Tegra K1 GPU of an Nvidia Shield K1 Tablet. The performance of this optimized and accelerated convolutional layer is compared with its sequential and heterogeneous versions. Results show that the proposed scheme significantly improves the overall results including energy efficiency, storage requirement and inference performance. In particular, the proposed scheme on embedded GPUs is hundreds of times faster than the sequential version and delivers tens of times higher performance than the heterogeneous approach
Magnetic materials and water treatments for a sustainable future
No full textAfter a brief historical classification of the main discoveries related to magnetism, magnetic materials have been rationally ordered in a simple (and hopefully clear) organization. A great effort was realized in the description of the different synthetic approaches for the preparation of magnet-sensitive materials (in particular, focusing on iron oxides). The principal useful techniques for evaluating the magnetic properties in materials (namely, MFM and magnetization hysteresis) have been presented, providing useful examples in order to understand both the potentiality and limits of these characterization methods. Finally, the application of magnet-sensitive materials in water remediation processes has been provided, highlighting both advantages and disadvantages of their use compared to conventional treatments. In this context, the action mechanism and the possible integration of this class of materials into processes involving wastewater treatments are widely discussed, keeping an eye toward the future perspectives
Models to Estimate Energy Requirements for Iron and Steel Industry: Application Case for Electric Steelworks
No full textNowadays the price of electricity depends on many factors; the introduction of renewable energy sources has changed the basics of electricity production and the determination of energy price. Iron and steel industries have the necessity to forecast the power amount they are going to spend: today production planning is performed without taking into account that the difference in electricity price between night and day can overcome 500%. The aim of this work is to create a model able to estimate energy requirements for iron and steel industry; the model correctness is assessed, for both energy and power analysis, by comparison with real data. The provisional planning tool is employed to provide data to a computer platform able to assess, on the basis of required energy, the best market on which power can be purchased in view of a money saving for the Company