57 research outputs found

    Manufacture Techniques of Chitosan-Based Microcapsules to Enhance Functional Properties of Textiles

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    In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances. This chapter reviews the use of microencapsulation technique as an approach to effectively apply chitosan to the textile material while overcoming the significant limitations of finishing processes. The assembly of chitosan macromolecules into microcapsules was proved to boost the biological properties of the polymer thanks to a considerable increase in the surface area available for interactions with the living tissues. Moreover, the incorporation of different active substances into chitosan shells allows the design of multifunctional materials that effectively combine core and shell properties. Based on the kind of substances to be incorporated, several encapsulation processes have been developed. The literature evidences how the proper choices concerning encapsulation technology, chemical formulations, and process parameter allow tuning the properties and the performances of the obtained microcapsules. Furthermore, the microcapsules based finishing process have been reviewed evidencing how the microcapsules morphology can positively interact with textile substrate allowing an improvement in the durability of the treatment. The application of the chitosan shelled microcapsules was proved to be capable of imparting different functionalities to textile substrates opening possibilities for a new generation of garments with improved performances and with the potential of protecting the user from multiple harms. Lastly, a continuous interest was observed in improving the process and formulation design in order to avoid the usage of toxic substances, therefore, complying with an environmentally friendly approach

    Realism vs. Reality in Digital Reconstruction of Cities

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    The digital reconstruction of existing cities using virtual reality techniques is being increasingly used. For consultants, municipalities and planning departments these models provide decision support through visual simulations (El Araby, 2001). For academia they provide a new tool for teaching students urban design and planning (Okeil, 2001). For authorities they provide a tool for promoting the city on the world wide web trying to attract more businesses and tourists to it. The built environment is very rich in detail. It does not only consist of open spaces surrounded by abstract buildings but it also includes many smaller objects such as street furniture, traffic signs, street lights, different types of vegetation and shop signs for example. All surfaces in the built environment have unique properties describing color, texture and opacity. The built environmentis dynamic and our perception is affected by factors such as pedestrian movement, traffic, environmental factors such as wind, noise and shadows. The built environment is also shaped by the accumulation of changes caused by many influences through time. All these factors make the reconstruction of the built environment a very complex task. This paper tries to answer the question: how realistic the reconstructed models of urban areas can be. It sees “Realism” as a variable floating between three types of realties. The reality of the physical environment which we are trying to represent. The reality of the digital environment which will host the digitally reconstructed city. And the reality of the working environment which deals with the problem of limitation of resources needed to digitally reconstruct the city. A case study of building a 3D computer model of an urban area in the United Arab Emirates demonstrates that new time-saving techniques for data acquisition can enhance realism by meetingbudget limitations and time limitations

    Partial Continuity in Bridge Girders with Jointless Decks

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    Em\u27body\u27ing Virtual Architecture: the Third International Conference of the Arab Society for Computer Aided Architectural Design

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    The increasing speed of technological improvements outpaced many design issues. Nowadays, architecture is accepting digital design tools and technologies as a feature integrated in design process and in spaces of our everyday “Being-in-the-World”. The consequences of this integration result in many changing and expanding forms of interaction
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