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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.
- 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
- Conducting Polymer‐Based Flexible Supercapacitor DevicesPublication . Torvi, Anand I.; Naik, Satishkumar R.; Hegde, Sachin N.; Mulla, Mohemmedumar; Kamble, Ravindra R.; Mitchell, Geoffrey R.; Kariduraganavar, Mahadevappa Y.Flexible supercapacitors are gaining considerable attention because of their wide range of applications in the area of flexible electronics. Significant opportunities exist and will continue to exist for the development of flexible energy storage devices through intensive research. The level of R&D activity in the general field of energy storage technology has been rising considerably all over the world during the last two decades, because of the growing recognition of the commercial potentialities of energy storage technology. This chapter focuses on the different types of conducting polymer-based supercapacitors, incorporating polymers such as polyaniline, polypyrrole, polythiophene, and the derivatives of polythiophene. Emphasis is given to the methods of fabricating flexible supercapacitor devices. The different electrolytes employed for the development of flexible supercapacitors are discussed. In the beginning, a brief account of the principles and classification of supercapacitors is described. The chapter concludes with a consideration of the prospects for flexible supercapacitor. To compile this chapter and to provide adequate information to the readers, we have explored all the possible materials available in the literature.
- 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).
- Design of Pyrolysis System to Convert Waste Plastic to FuelsPublication . Oliveira, Nelson S.; Pardo, Michael; Capela, Carlos; Gaspar, Marcelo; Vasco, Joel; Heleno, LizeteThe conventional recycling technology to process waste plastic, mechanical recycling, is not suitable to recycle waste thermoplastic with high content of contamination. Pyrolysis is a promising technology since it can convert into valuable products, such as fuels and monomers. This study focused on the design of the pyrolysis equipment for waste plastic based on polyolefins. The feeder of waste plastic is a worm screw conveyor that will be in a pre-heating system. The batch reactor has support for catalyzer and can operate between 300 up to 600 ºC with attached induction system for heating. The output flows into condenser in series to separate two liquid phases and gases, depending on its boiling point. The 3D model was done with SolidWorks, control system modelled in CADe SIMU and particle simulation with FloXpress.
- 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.
- 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.
- 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.
- PrefacePublication . Fernandes, Paulo Rui; Bártolo, Paulo JorgeThis book is a contribution for Tissue Engineering seen as multidisciplinary field involving scientists from different backgrounds like medicine, chemistry, material science, engineering and biology with a focus on the development of mathematical methods that are quite relevant to understand cell biology and human tissues as well to model, design and fabricate optimized and smart scaffolds.
- PrefacePublication . Mitchell, GeoffreyRheology is the study of the flow of matter, primarily in the liquid state, but also as 'soft solids' or solids under flow conditions in which they respond with plastic flow rather than deforming elastically in response to the applied force. An understanding of the flow of matter underpins a diversity of technologies and industrial processing including polymer and food processing. It applies to substances which have a complex microstructure, such as concentrated solutions, suspensions, polymers and inorganic glass formers as well as biological materials which belong to the class of soft matter. Rheological measurements are seemingly straightforward to make, but require models to interpret the mechanical measurements in terms of the microscopic behaviour of the material. A complementary approach is to perform structural characterisation of the material during the rheological measurements in order to observe directly the microscopic reorganisation which accompanies the flow. "Rheology: Theory, Properties and Practical Applications" draws these diverse strands of current rheological research in to a single volume which embraces theory, measurement and applications in topics as diverse as theory and electrospinning, coal ash slag and food processing, hydrogels and liquid crystal polymers, reaction injection moulding and microreheology. There is a strong focus on the emerging topics in rheology and its application to complex soft matter especially in the field of food science and technology. The sixteen chapters in the volume present unpublished research work across these topics from leading authorities in the relevant field. The volume has a strong international representation with the selected authors drawn from some ten countries in Europe, South America and the rest of the world. Each chapter contains a comprehensive bibliography of related work. "Rheology: Theory, Properties and Practical Applications" provides a fascinating snap shot across the current developments in rheology. (Imprint: Nova)