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Percorrer CDRsp - Capítulos de livros por Objetivos de Desenvolvimento Sustentável (ODS) "09:Indústria, Inovação e Infraestruturas"
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- 3D shape prior active contours for an automatic segmentation of a patient specific femur from a CT scanPublication . Almeida, D.; Folgado, J.; Fernandes, P.R.; Ruben, RuiThe following paper describes a novel approach to a medical image segmentation problem. The fully automated computational procedure receives as input images from CT scan exams of the human femur and returns a three dimensional representation of the bone. This patient specific iterative approach is based in 3D active contours without edges, implemented over a level set framework, on which the evolution of the contour depends on local image parameters which can easily be defined by the user but also on a priori information about the volume to segment. This joint approach will lead to an optimal solution convergence of the iterative method. The resulting point cloud can be an excellent starting point for a Finite Element mesh generation and analysis or the basis for a stereolitography for example.
- Augmented Reality and 3D Technologies: Mapping Case Studies in EducationPublication . Cardoso, Teresa; Coimbra, Teresa; Mateus, ArturLearning anywhere, anytime is becoming ever more a daily routine, due to the increasing and recent growth of information and communication technologies. In the last 5 years, their key characteristic and specifically in the use of mobile equipment and software have been their portability, mobility, and network access. The technological development, including software applications available for the implementation of three-dimensional contents, has been following this trend. Hence, it is important to know whether and how these threedimensional contents are being integrated in educational situations, namely, regarding augmented reality and mobile learning. Thus, a synthesis of Portuguese and international research works and case studies on the use of threedimensional augmented reality is chronologically presented along with the evolution of information and communication technologies. The main goal of this knowledge mapping is to contribute to the state of the art in threedimensional augmented reality technologies in education. In addition, it is aimed at framing the creation and implementation of three-dimensional content in higher education, specifically in the field of mathematics. © Springer-Verlag Berlin Heidelberg 2015.
- Chapter 13. Future Perspectives on ElectrospinningPublication . Mitchell, Geoffrey R.; Sperrin, MalcolmAlthough the origins of electrospinning date back over 100 years, it is intense activity in the last 21 years which has led to considerable improvements in our knowledge of electrospinning and the broad-ranging opportunities for commercial application. The recent development of melt electrospinning provides a new additive manufacturing tool, providing routes to structures from nanometres to millimetres. Here, we consider where this rollercoaster of a topic is heading and its future prospects.
- Chapter 8: Structure Development in Electrospun FibresPublication . Mitchell, Geoffrey R.; Mohan, Saeed D.; Davis, Fred J.; Ahn, Kyung-Hwa; Al-Azab, Mohamed; El Hadi, Ahmed; Elliott, Delyth; Kariduraganavar, Mahadevappa Y.; Nagarajan, Anitha; Nazhipkyzy, Meruyert; Geoffrey R MitchellElectrospinning is a process which transforms polymer solutions in to solid fibres in ∼25 ms. In the case of an amorphous polymer, the resultant molecular organisation may not be so different from that of the solution. However, polymers are rich in different types of ordering processes and these may be encountered during electrospinning. In many areas of polymer processing, the processing procedures can have a significant impact on the structure and hence properties of the final product as the selection of the chemical configuration
- Controlling Morphology Using Low Molar Mass NucleatorsPublication . Mitchell, Geoffrey; Wangsoub, Supatra; Nogales, Aurora; Davis, Fred J.; Olley, Robert H.Crystallisation is a hugely important process in physical sciences and is crucial to many areas of, for example, chemistry, physics, biochemistry, metallurgy and geology. The process is typically associated with solidification, for example in the purification of solids from a heated saturated solution familiar to all chemistry undergraduates. Crystalline solids are also often the end result of cooling liquids, or in some cases gases, but in order to form require nucleation, in the absence of nucleation supercoiling of liquids well below the melting point is possible (Cava-gna, 2009). The quality of crystals, as gauged by size and levels of order is highly variable, and may depend on factors such as material purity and the rate of cool-ing; rapid cooling may result in poor crystallisation, or even the formation of amorphous materials with no long range order. In geological systems rates of cooling may vary over many orders of magnitude, for example obsidian is a large-ly amorphous material produced when lava is rapidly cooled (Tuffen, 2003), while the gypsum crystals found in the Cueva de los Cristales in Chihuahua, Mexico can reach 10 metres in length (Figure 1) and are formed over hundreds of thousands of years. In this latter case the formation of such large spectacular structures as shown in Figure 1 can only be explained by a low nucleation rate (García-Ruiz, 2007; Van Driessche, 2011).
- Direct Digital Manufacturing: A Challenge to the Artistic Glass ProductionPublication . Felismina, R.; Silva, M.; Mateus, A.; Malça, C.Currently the high hand-labor costs, long production times, lack of automation and high energy consumption associated with the high temperatures required to produce pieces of glass, are identified as the main inhibitors of growth and economic development of the decorative and utility glass industrial sector. Current production processes impose limitations on the complexity of the geometry and shape of the glass pieces to be produced, which in turn greatly restricts the creativity of designers and consequently, the characteristics of differentiation and innovation presented by new products on the market.
- Electrospinning for Medical ApplicationsPublication . Song, Wenhui; Mitchell, Geoffrey R.; Burugapalli, KrishnaThere is a natural connection between a variety of electrospun fibres and biomedical applications. The most commonly quoted application of electrospun fibres is their use as scaffolds in tissue engineering for regenerative medicine. There are also many other applications, which include drug delivery systems, membrane systems and analytical functionality. This chapter identifies the key challenges in each of these topics, as well as the particular role of electrospun fibres in addressing these challenges.
- IntroductionPublication . Davis, Fred J.; Mohan, Saeed D.; Ibraheem, Muaathe A.This chapter provides a basic introduction to the topics described in this book. The principles of electrospinning, in terms of the influence of an electric field on a droplet of polymer melt or solution is introduced, and a review of some of the experimental parameters, and their relationship towards the properties of the fibres produced is given. A brief summary of the types of materials that can be electrospun is included, together with methods for their characterisation. Finally, a short review of potential applications for electrospun fibres is discussed.
- Permeability Evaluation of Flow Behaviors Within Perfusion BioreactorsPublication . Freitas, D.; Almeida, H.A.; Bártolo, P. J.Tissue engineering aims to produce artificial tissue in order to create or repair damaged tissue. It is evident that scaffolds are of extreme importance, because they will be the support structure of the new tissue. This new tissue is cultivated in vitro in a bioreactor in which is placed the scaffold. In order to control the cell culture process inside of a bioreactor, it is essential to know the fluid flow inside the scaffold for an adequate exchange of nutrients and metabolic waste. A novel multifunctional bioreactor with a perfusion system module comprised of three different inlet and outlet membranes is being developed. This research work will evaluate the permeability of the scaffold under the three different inlet and outlet diffusion membranes of the culture chamber.
- Photocrosslinkable Materials for the Fabrication of Tissue-Engineered Constructs by StereolithographyPublication . Pereira, Rúben F.; Bártolo, Paulo J.Stereolithography is an additive technique that produces three-dimensional (3D) solid objects using a multi-layer procedure through the selective photoinitiated curing reaction of a liquid photosensitive material. Stereolithographic processes have been widely employed in Tissue Engineering for the fabrication of temporary constructs, using natural and synthetic polymers, and polymer-ceramic composites. These processes allow the fabrication of complex structures with a high accuracy and precision at physiological temperatures, incorporating cells and growth factors without significant damage or denaturation. Despite recent advances on the development of novel biomaterials and biocompatible crosslinking agents, the main limitation of these techniques are the lack number of available photocrosslinkable materials, exhibiting appropriate biocompatibility and biodegradability. This chapter gives an overview of the current state-of-art of materials and stereolithographic techniques to produce constructs for tissue regeneration, outlining challenges for future research.